1. BACSICH, P., and RIDD EI L, W. J. B (1945). Natiure, Lonid., 155, 271.
2. BESSEY, C). A., and WOLBACH, S. B. (1939). J. Exp. Med., 69, 1.
3. CANMPBELL, F. W, and 'MICHAELSON, 1. C. (1949). British Jolurnal of Ophthalmnology, 33, 248.
4. FERGUSON, I. D., and GARRY, R. C. (1950). Brit. J. Nuitrit. (in thepress).
5. COGAN, D. G. (1949). Arch. Ophthal., Cliscago, 41.